Texas Instruments BoosterPack AM2 BLDC Series User manual

EVM User's Guide: BP-AM2BLDCSERVO
AM2x BLDC Servo Motor BoosterPack (BP-
AM2BLDCSERVO)
Description
The AM2x BLDC Servo Motor BoosterPack (BP-
AM2BLDCSERVO) is an add-on for the Sitara
AM2x MCU LaunchPad development boards which
provides a networked, industrial BLDC servo
development platform. Compatible with the AM243x
(LP-AM243) and the (AM263x) LP-AM263 LaunchPad
development boards, this BoosterPack provides up to
two axes BLDC 3-phase motor drive, in-phase current
feedback, Sigma-Delta current feedback, industrial
absolute encoder, and a single axis of resolver
feedback.
The attached AM2x LaunchPad natively provide an
array of industrial Ethernet, CAN, UART, LIN and
other connectivity and control peripherals of the AM2x
MCU. Together this LaunchPad and BoosterPack
system provide a complete platform for prototyping
networked, industrial BLDC servo drives.
Get Started
Texas Instruments™ offers the MCU+ Academy as
a resource for designing with the MCU+ software
and tools on supported devices. The MCU+ Academy
features easy-to-use training modules that range from
the basics of getting started to advanced development
topics.
Features
• BOOST-XL TI BoosterPack Design - 80 digital/
analog I/O compatible with AM2x LaunchPad
Development Kits
• Two axes of 3-phase BLDC motor drive with the
DRV8316R 24 V/8A monolithic gate drive and
amplifier bridges
• Two axes (6 channels) of 3-phase current
feedback through AMC1035D Sigma-Delta
modulator and INA241A current sense path
• Two axes of RS-485 based absolute encoder
feedback supporting multiple industrial encoder
standards
• Single-axis of resolver feedback
Applications
•Servo drive communication module
•Servo drive control module
•Servo drive position feedback
•Servo drive position sensor
•Servo drive power stage module
LP-AM243 LaunchPad Attached to BP-AM2BLDCSERVO BoosterPack
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1 Evaluation Module Overview
1.1 Introduction
The BP-AM2BLDCSERVO BoosterPack kit, when attached to a compatible AM2x MCU LaunchPad MCU board,
provides an industrial BLDC servo drive development platform.
A reference software/hardware solution based on the AM243x (ALX) 2-axis servo reference system is shown in
the figure below. Together the BP-AM2BLDCSERVO and the LP-AM243 LaunchPad can be used to experiment
with this and similar networked industrial servo drive architectures.
Figure 1-1. AM243x Based BLDC Motor Drive - 2-Axis BLDC Servo Scenario
By using the AM2x dual-R5F cores along with the Programmable Real-time Unit (PRU) cores, the AM2x MCU
are able to create a flexible hardware and software architecture. This supports a wide range of industrial
real-time Ethernet standards and industrial absolute encoder standards while also taking care of the core control
loop and monitoring tasks.
1.2 Kit Contents
The only item that comes with this kit is the BP-AM2BLDCSERVO PCB assembly itself.
Additional required components, per motor axis (not included in this kit):
• 24 V (nominal), 8A (max) bench DC supply
• 3-Phase, BLDC motors - maximum 8A (RMS) current draw
• Absolute position encoders running on EnDat22, HDSL, or Tamagawa protocols
If you have any feedback or questions, support for the Sitara MCU and this BP-AM2BLDCSERVO kit is provided
by the TI Product Information Center (PIC) and the TI E2E™ Forum. Contact information for the PIC can be
found on the TI website. Additional device-specific information can be found in the Section 5.
1.3 Specification
The BP-AM2BLDCSERVO is divided up into axis-1 and axis-2 component channels with a few common system
components. All motor control I/O from the attached MCU are passed through the BoosterPack headers. Screw
terminals are used to provide a quick attachment point for bench DC power and attaching BLDC motor drive
output.
Axis-1 and axis-2 channels both include a DRV8316 BLDC 3-phase motor driver, RS-485 transceiver set
for 2-wire and 4-wire absolute encoder communication, and AMC1035D based Sigma-Delta current feedback
channels for each 3-phase motor driver output.
Additionally, axis-1 includes direct INA241A current sense amplifier feedback channels for MCU ADC sampling
and a resolver excitation and receiver amplifier network.
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The encoder RS-485 transceivers and resolver amplifier I/O are routed to Dsub15 female connectors and
optional 100-mil pitch headers that are routed in line with minimal distance between them. This gives a standard
connector interface as well as the flexible prototyping headers to account for different encoder and resolver
pinouts.
Figure 1-2. BP-AM2BLDCSERVO System Block Diagram
1.4 Device Information
This BoosterPack is part of the LaunchPad development kit ecosysem for Sitara™ Microcontrollers Family of
Arm® Cortex®-R based high performance microcontrollers. With advanced networking, real-time control, and
signal processing accelerators these MCU meet the emerging and dynamic requirements for industrial and
automotive applications.
This BoosterPack is intended to operate with the Sitara Microcontrollers - LaunchPad Evaluation Modules. TI
provides device-specific Evaluation Module (EVM) designs to help kick-start product development. See the
AM263x LaunchPad and AM243x LaunchPad for more information.
The following list highlights the primary devices used in the design of this BoosterPack evaluation kit.
•DRV8316: 40-V max 8-A peak 3-phase motor driver with integrated current sensing. This device is used to
provide the MCU with a motor drive bridge network to drive the attached 3-phase BLDC motors.
•INA241A: -5-V to 110-V bidirectional ultraprecise current sense amplifier with enhanced PWM rejection. An
array of INA241A are used as the shunt current sense amplifier to provide 3-phase current feedback from the
DRV8316 motor driver.
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•AMC1035: Precision delta-sigma modulator with ±1-V bipolar input and 2.5-V reference output. An array of
AMC1035 are used to provide a Sigma-Delta digital modulation for the current sense feedback.
•LMK1C1108: 8-channel output LVCMOS 1.8-V buffer. Used to distribute Sigma-Delta clocks from the
attached MCU to the array of AMC1035 modulators.
•THVD1450D: 3.3-V to 5-V RS-485 transceiver with ±18-kV IEC ESD protection. Multiple THVD1450 are used
to provide RS-485 transceiver and line-driver capability for the 3.3V MCU absolute encoder interfaces.
•LM74502: 3.2-V to 65-V industrial RPP controller with load disconnect and OVP. These devices are used to
provide over-voltage and reverse-polarity protection to the motor and encoder distribution network.
Many other devices were used in the construction of this evaluation kit as well. Please see the BP-
AM2BLDCSERVO Board Design Files for details.
1.5 Important Usage Notes
Thermal Warning
Note
The BP-AM2BLDCSERVO includes two motor driver amplifier devices, U6 and U7 (Texas Instruments
Part Number DRV8316RRGFR) which can exceed 55 C case temperature during normal operation.
The following additional PCB silkscreen and this user's guide statement has been added to alert users
to these higher temperature components.
Caution
Caution hot surface.
Contact can cause burns.
Do not touch!
Mechanical Warning
Note
This kit assembly does not include any mechanical components. However, normal usage of this
assembly requires attaching motors, encoders and resolvers to compatible terminals and connectors
of the board.
!
Warning
Warning: Moving parts.
Do not touch the spinning disk or motor
during operation.
TI has not performed specific safety assessments on motor, encoder or resolver components that is used with
this kit. Users of this kit are advised to follow all usage, maintenance and safety recommendations provided
by the selected accessory component manufacturers. Caution must observed in the usage of all accessory
components.
Power Supply Usage
Note
The BP-AM2BLDCSERVO requires up to two external power supplies to function. No power supplies,
cables or adapters are included in this kit.
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Note
External Power Supply Requirements:
• J5 and J6 terminal blocks (Phoenix Contact Part Number 1711725) are used as power input
• J5 and J6 terminal blocks accept 12-30 AWG wire. Multistranded 16 AWG, or larger diameter,
recommended.
• Input voltage: 9-24 Volts (nominal), 36 Volts (max)
• Max input current: 8 Amps
Note
TI recommends using an external power supply or accessory which complies with applicable regional
safety standards such as (by example) UL, CSA, VDE, CCC, PSE.
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2 Hardware
2.1 Assembly Instructions
The following assembly steps must be followed when starting with a new BP-AM2BLDCSERVO BoosterPack
and a new LP-AM2x LaunchPad.
1. BP-AM2BLDCSERVO and LP-AM2x LaunchPad are both powered down.
2. BP-AM2BLDCSERVO and LP-AM2x LaunchPad can be attached through their LaunchPad connectors.
3. Attach LP-AM2x LaunchPad power and debugging cable (if necessary) and keep LaunchPad unpowered.
4. Attach 24 V DC supply (current limit to 8A) to the BoosterPack screw terminals and keep supply powered off.
5. Attach motor drive output to the BoosterPack screw terminals.
6. Attach encoder power/data cable/wires to the BoosterPack Dsub15 connectors or 100-mil pitch headers.
7. Attach resolver power/data cable/wires to the BoosterPack Dsub15 connectors or 100-mil pitch headers.
8. Verify that all motor and encoder shafts are free and clear of obstructions prior to powering on and testing
system.
Figure 2-1. LP-AM243 mated to BP-AM2BLDCSERVO
2.2 Power Requirements
After assembly, the following power-on and power-off sequence must be followed when working with the BP-
AM2BLDCSERVO kit.
The LP-AM2x 5.0V and 3.3V BoosterPack pins provide system-level 5.0V and 3.3V power for the attached
BP-AM2BLDCSERVO kit, including indicator LED power and various logic-default pull-up resistor voltages.
Power-On Sequence
Follow the steps below to power on the device:
1. Power on the LP-AM2x LaunchPad.
2. Power on the 24 V DC supply for the BoosterPack.
3. Load and run LP-AM2x LaunchPad application over attached XDS110 debugger and Code-Composer
Studio debug session.
Power-Off Sequence
Follow the steps below to power off the device:
1. Power-off the 24V DC supply for the BoosterPack.
2. Power-off the LP-AM2x LaunchPad.
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2.3 Interfaces
Major Components and Location
The below figures show the location of major connectors, components and circuit functions used on this design.
BP-AM2BLDCSERVO Top View, Major Component Areas and Connectors Highlighted
Figure 2-2. BP-AM2BLDCSERVO Top View, Major Component Areas and Connectors Highlighted
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Figure 2-3. BP-AM2BLDCSERVO Bottom View, Major Component Areas and Connectors Highlighted
Figure 2-4. BP-AM2BLDCSERVO Top View - Connectors and Cables Overview
Typical Usage
A typical setup for an axis-1, BLDC motor control scenario is shown below. The bench power, motor drive output
and absolute encoder cables are shown attached. The attached LP-AM243 is shown with USB-C power and
XDS110 debugger cable also attached.
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Figure 2-5. BP-AM2BLDCSERVO and LP-AM243 LaunchPad - Axis-1 Power, Motor and Encoder cables
attached
2.4 LaunchPad Specific Features
Based on available LaunchPad I/O pinout, and specific MCU peripheral availability, each AM2x LaunchPad
supports a subset of the overall available features made available by this BP-AM2BLDCSERVO BoosterPack.
Additionally, only a subset of available hardware features have been fully incorporated into the AM243
and AM263 MCU SDK or made available through demo application through dev.ti.com. These supported,
unsupported and future features are outlined in the tables below. These tables are updated a new features are
tested and made available.
Table 2-1. Currently Supported Features
Feature AM243x LaunchPad
LP-AM243 Rev E3
AM243x LaunchPad
LP-AM243 Rev A
Axis-1 BLDC Driver Yes Yes
Axis-2 BLDC Driver No Yes
Axis-1 SDFM Current Feedback Yes Yes
Axis-2 SDFM Current Feedback No Yes
Axis-1 Current Feedback No No
Axis-2 Current Feedback No No
Axis-1 Absolute Position Encoder Yes Yes
Axis-2 Absolute Position Encoder No Yes
Axis-1 Resolver Position No No
The below table captures the planned features as testing, MCU SDK development and demo application work
continue with this kit.
Table 2-2. Planned/Future Features
Feature AM263x LaunchPad
LP-AM263 Rev E2
AM263x LaunchPad
LP-AM263 Rev A
Axis-1 BLDC Driver Yes Yes
Axis-2 BLDC Driver No Yes
Axis-1 SDFM Current Feedback Yes Yes
Axis-2 SDFM Current Feedback No Yes
Axis-1 Current Feedback No No
Axis-2 Current Feedback No No
Axis-1 Absolute Position Encoder Yes Yes
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Table 2-2. Planned/Future Features (continued)
Feature AM263x LaunchPad
LP-AM263 Rev E2
AM263x LaunchPad
LP-AM263 Rev A
Axis-2 Absolute Position Encoder No Yes
Axis-1 Resolver Position No No
2.5 Jumper Information
This section describes the jumper selectable options on this board. See table and figures below for list of
available jumper options, details and configuration defaults. Additional jumper details are located in each the
major
Note
These static jumper configurations must be checked and set prior to running different motor control
scenarios.
Figure 2-6. Layout Top View - Jumper Locations
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Table 2-3. Jumper Configuration Options
Axis Jumper Function Default LP-AM243x
Configuration
Default LP-AM263x
Configuration
Both J11 VSENSE/ISENSE Select
Jumper pins 1-2 shorted: Select
Axis-1, Phase-A INA241 current sense
output routed to BoosterPack J15.24
Jumper pins 2-3 shorted: Select
Axis-2 DRV8316 VSENSE Phase-A
Output routed to BoosterPack J15.24
Jumper installed across pins
2-3
Routes optional motor
VSENSE into GPADC input
Jumper installed across pins
1-2
Routes required motor
ISENSE into SAR ADC input
J13 VSENSE/ISENSE Select
Jumper pins 1-2 shorted: Select
Axis-1, Phase-B INA241 current sense
output routed to BoosterPack J15.24
Jumper pins 2-3 shorted: Select
Axis-2 DRV8316 VSENSE Phase-B
Output routed to BoosterPack J15.24
Jumper installed across pins
2-3
Routes optional motor
VSENSE into GPADC input
Jumper installed across pins
1-2
Routes required motor
ISENSE into SAR ADC input
J26 VSENSE/ISENSE Select
Jumper pins 1-2 shorted: Select
Axis-1, Phase-C INA241 current sense
output routed to BoosterPack J15.24
Jumper pins 2-3 shorted: Select
Axis-2 DRV8316 VSENSE Phase-C
Output routed to BoosterPack J15.24
Jumper installed across pins
2-3
Routes optional motor
VSENSE into GPADC input
Jumper installed across pins
1-2
Routes required motor
ISENSE into SAR ADC input
J17 SDFM Clock Feedback Select
Jumper pins 1-2 shorted:
Jumper pins 2-3 shorted: asdad
Jumper Uninstalled
Function not used
J27/J28 Encoder/SDFM MUX Select
J27/J28 uninstalled: selects AM243x
SDFM and Encoder Paths
J27/J28 installed: selects AM263x
SDFM and Encoder Paths
J27 uninstalled J27 Installed
Axis-1 J18/J19 Encoder/Resolver Voltage Select
J18 installed: sets VSENSOR1 to 12
V
J19 installed: sets VSENSOR1 to
5.0V
Note: only one jumper must be
installed at a time during operation.
J19 Installed
This defaults VSENSOR1 to
5.0V compatible with most
absolute encoders.
J19 Installed
This defaults VSENSOR1 to
5.0V compatible with most
absolute encoders.
J22 SDFM Manchester Encoding Select
Uninstalled: Manchester encoding
disabled
Installed: Manchester encoding
enabled
J22 uninstalled J22 uninstalled
J24 RS485 Absolute Encoder
2-Wire/4-Wire MUX Select
Uninstalled: RS-484 4-Wire Path
Selected
Installed: RS-485 2-Wire Path
Selected
J24 uninstalled
Compatible with Heidenhain
EnDat22
Encoders
J24 uninstalled
Compatible with Heidenhain
EnDat22
Encoders
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Table 2-3. Jumper Configuration Options (continued)
Axis Jumper Function Default LP-AM243x
Configuration
Default LP-AM263x
Configuration
Axis-2 J20/J21 Encoder/Resolver Voltage Select
J20 installed: sets VSENSOR2 to 12
V
J21 installed: sets VSENSOR2 to
5.0V
Note: only one jumper must be
installed at a time during operation.
J21 Installed
This defaults VSENSOR2 to
5.0V compatible with most
absolute encoders.
J21 Installed
This defaults VSENSOR2 to
5.0V compatible with most
absolute encoders.
AM243x/AM263x ISENSE/VSENSE Select
The below diagrams describe the select path used to choose between Axis-1 in-phase current sense and Axis-2
voltage sense into a set of LaunchPad ADC channels. The Axis-1 in-phase current sense path is only usable
with the AM263x LaunchPad SAR ADC channels.
Figure 2-7. Axis-1 ISENSE/VSENSE Select - Jumper J11, J13, and J26 Configuration
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Figure 2-8. Axis-1 ISENSE/VSENSE Select - Layout/Schematic Excerpt for Jumper J11, J13, and J26
AM243x/AM263x PRU Encoder/Sigma-Delta MUX
The below diagrams describe the MUX path used to de-MUX and MUX a set of overlapping but conflicting
pins to the AM2x MCU AM243x and AM263x LaunchPad. Select lines for these MUX paths are either jumper
selectable.
Figure 2-9. PRU SDFM/Absolute Encoder MUX – Jumper J27 and J28 Configurable
PRU Sigma-Delta Modulator Clock Path Select
The below diagrams describe the select path used to choose between the different PRU Sigma-Delta Modulator
(SDFM) feedback clocks. The SYNC0 and SYNC1 paths from the PRU are used to generate two different clocks
that can be used for both clocking data out of the attached SDFM AM1035 transceivers as well as clocking data
into the AM2x MCU.
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Figure 2-10. PRU Sigma-Delta Modulator Clock Path Select – J17
Figure 2-11. BP-AM2BLDCSERVO Layout - Layout/Schematic Excerpt for PRU SDFM Clock Path Select –
J17
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2.6 Mechanical
The following tables and figures present the overall mechanical dimensions, BoosterPack connector relative
placement and mounting hole dimensions and locations. For further mechanical detail please refer to the board
design file package where STEP 3D model files have been provided. This STEP model was exported from the
source Altium Designer CAD package.
Table 2-4. BP-AM2BLDCSERVO PCB Assembly Dimensions
Dimension Value Unit
Overall Width 8000 Mils
Overall Depth 4300 Mils
Overall Height 1190.90 Mils
Mount Hole Diameter 144.0 Mils
Figure 2-12. BP-AM2BLDCSERVO PCB Assembly – Top View
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Figure 2-13. BP-AM2BLDCSERVO PCB Assembly – Bottom View
Figure 2-14. BP-AM2BLDCSERVO PCB Assembly – Front/Back View
Mounting Holes
The board includes 4x 144 mil diameter corner mounting holes. An additional 8x 144 mil diameter holes match
the LP-AM243 and the LP-AM263 LaunchPad to allow the LaunchPad boards to be secured through standoffs.
For basic usage, the LaunchPad 80-pin connectors provide a strong retention force.
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2.7 System Power
The BP-AM2BLDCSERVO power tree is divided between motor axis-1, motor axis-2 and common digital and
analog supplies. 24 V DC power is provided through the J5 and J6 screw-terminals. After passing through
over-voltage/reverse-polarity protections, this supply is used to directly power the BLDC motor drivers and
encoder/resolver on-board regulators.
When motor bench power is applied to the J5 and J6 terminal blocks, the U2/U3 over-voltage and reverse
polarity circuits are powered. J5 and J6 can be powered from the same bench source or different bench sources,
allowing for different motor voltages to be used on each axis.
In normal condition, the J5/J6 bench power will power the BLDC motor drivers and the Encoder/Resolver
regulators. In an over-voltage or reverse polarity state, the LM74502 NFET switch path remains in a high
impedance state, protecting the downstream devices. Over-voltage protection disables the power to the system
if J5/J6 exceeded. Reverse polarity protection disables the power to the system if the J5/J6 negative voltage
terminal exceeds the positive voltage terminal.
Motor and Encoder Bench Power
After bench supply power-on through J5/J6, the encoder/resolver connectors are initially disconnected from their
regulator by way of the U5/U40 load switches. This prevents typical high inrush currents from attached encoders/
resolvers from effecting regulator power-on and feedback loop stabilization. GPIO control from the attached
LaunchPad is required to enable the U5/U40 load switches and power on the attached encoders/resolves.
Note
Encoder output power through U4 and U39 buck-converter is selected through a jumper selector. See
Section 2.5 for a description of all jumper configuration option descriptions.
Figure 2-15. Motor Axis-1 Power Distribution
Figure 2-16. Motor Axis-2 Power Distribution
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System Digital/Analog Power
The LaunchPad 3.3V/1A supply is used to power all of the BP-AM2BLDCSERVO 3.3V logic and analog
loads. See the below diagram of the 3.3V derived power tree. VSYS_3V3 power is applied from the attached
LaunchPad pins as soon as the LaunchPad is powered on.
This powers on all of the 3.3V powered digital loads such as the AMC1035 Sigma-Delta modulators, the
sigma-delta clock distribution components. Through an LC filter, the also power on the onboard VREF sources,
and current sense paths making all of these components ready to send SDFM/current sense data back to the
attached MCU.
Figure 2-17. Common 3.3V Digital and Analog Power Tree
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2.8 BLDC Motor Drive
The BP-AM2BLDCSERVO provides up to two axes of 3-phase, 24 Volt, 8 Amp (peak) BLDC motor drive. Each
axis utilizes a DRV8316 monolithic gate-driver and 3-phase half-bridge to provide phase power to the attached
BLDC motors. The AM2x MCU control the DRV8316 through a set of GPIO enable and fault lines and a SPI
management bus. AM2x EPWM are used as gate-driver inputs.
Figure 2-18. Axis-1 DRV8316 Motor Drive
Figure 2-19. Axis-2 DRV8316 Motor Drive
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DRV8316 SPI management is through a single SPI BUS from the AM2x MCU LaunchPad is MUX’d between
both Axis-1 and Axis-2. The SPI MUX select line is controlled through an MCU GPIO.
Note
The BP-AM2BLDCSERVO design is primarily focused on providing evaluation of the MCU control,
feedback and networked peripherals. The DRV8316 driver is lower-current industrial driver used to
provide a minimum gate-driver and motor drive platform. This may not be a good choice for higher
current, or higher voltage BLDC servo applications.
Multiple current sense feedback are designed around these motor drivers. See Section 2.9 for a full description
of all of these paths.
See the DRV8316 data sheet for more information on this particular motor driver.
2.9 Motor Current Feedback
The BP-AM2BLDCSERVO supports multiple current feedback paths for current feedback control. Direct current
sense paths route current sense amplifier output directly to the AM263x SAR ADC LaunchPad channels. The
other path utilizes a set of onboard AMC1035 Sigma-Delta Modulator ADC and then routes the digital samples
to the PRU peripheral inputs of the AM2x device. Each path is designed to support the different current sense
capabilities of the attached AM2x MCU.
• The INA241A sense amplifiers provide the voltage proportional to the current through in-line resistors on
each motor output phase. This path is routed to AM263x SAR ADC pinout of the Launchpad connectors.
• The DRV8316 provides an internal sense and amplifier path for current through the low-side FET of each
half-bridge. See the for a full description of the different feedback paths. This path is routed to the AM263x
SAR ADC pinout of the LaunchPad connectors.
• The AMC1035 path provides sampled current feedback in a bitstream modulated format. This is intended to
be used with the AM2x PRU SDFM demodulation firmware.
Figure 2-20. Axis-1 Motor Current Feedback Paths
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